La métrologie des fréquences lumineu-ses fait progresser notre connaissance de la constante de Rydberg

摘要

As compared to the usual methods of interferometric measurement of wavelength, the direct measurement of optical frequencies improves by a extent the accuracy of spectroscopic experiments. The development of a new optical frequency standard (namely a semi-conductor laser locked on a two-photon transition in rubidium), and its absolute frequency calibration, allowed us to improve the accuracy of very high resolution spectroscopic experiments on hydrogen and deuterium beams. A new value of the Rydberg constant, with relative uncertainty of 10↑(-11), was derived from these measurements.